1. Field of the Invention
The present invention relates to a production method and apparatus of an interior trim component such as interior door panels, dashboards and the like for an automotive vehicle, and more particularly to a production method and apparatus of an interior trim component covered with plural kinds of surface skin materials in such a manner that the splice line of the surface skin materials is hidden within a groove or valley provided in a substrate of the trim component
2. Discussion of the Prior Art
For production of an interior trim component of this kinds, it is required to accurately position the splice line of surface skin materials in a molding die thereby to hide the splice line within a groove or valley provided in a substrate of the trim component. To satisfy the requirements, disclosed in Japanese Patent Laid-open Publication 61-230920 are a method of clamping each edge portion of surface skin materials to a stationary plate projected from a recessed portion of a molding die for formation of the groove or valley in the substrate, a method of retaining surface skin materials in place by overlapping the surface skin materials at their edge portions and sticking the overlapped edge portions to equally spaced needles projected from a stationary plate in a molding die, and a method of adhering each edge portion of surface skin materials to a stationary plate in a molding die by means of a double-faced adhesive tape.
In the first method described above, separate clips are used for clamping the surface skin materials to the stationary plate, resulting in an increase of the manufacturing cost. In the second method described above, it is required to make the stationary plate as thinner as possible for reducing the width of the groove or valley in the substrate. For this reason, thin needles used as the needles projected from the stationary plate are easily broken. In the third method, the adhesive force of the tape is decreased by use of two or three times. It is, therefore, required to replace the adhesive tape with new one. In any case, the surface skin materials have to be manually introduced into the molding die and mounted in place. Accordingly, the foregoing methods are unsuitable for mass-production of this kind of trim components.
It is, therefore, a primary object of the present invention to provide a production method and apparatus suitable for mass production of this kind of interior trim components.
According to the present invention, there is provided a production method of an interior trim component covered with a surface skin material having a plurality of different portions in such a manner that each boundary line of the different portions is hidden in a groove or valley provided in the substrate of the trim component, comprising the steps of introducing the surface skin material into a space between a pair of confronted molding dies and positioning the boundary line of the surface skin material in engagement with the corresponding internal projection formed on a molding surface of one of the molding dies; forwarding a thrust member assembled within the other molding die to be projected from its molding surface toward the internal projection of the confronted molding die and retractable therefrom and bringing a distal end of the thrust member into engagement with the boundary line of the surface skin material to retain the surface skin material in place on the internal projection of the confronted molding die; clamping the molding dies in a condition where the distal end of the thrust member is maintained in engagement with the boundary line of the surface skin material positioned on the internal projection; and injecting melted synthetic resin into a space between the molding dies to form a substrate of the trim component with the surface skin material in a condition where the thrust member is retracted by the melted synthetic resin filled in the space between the molding dies.
In the production method of the interior trim component, it is preferable that the surface skin material is in the form of plural kinds of surface skin materials preliminarily spliced at their edge portions, wherein the spliced portion of the surface skin materials is positioned in engagement with the corresponding internal projection of the molding die and retained in place by engagement with the distal end of the thrust member. It is also preferable that the thrust member is formed at its distal end with a recess for engagement with the surface skin material at its boundary line positioned in place on the internal projection of the molding die.
According to an aspect of the present invention, there is provided a production apparatus of an interior trim component covered with a surface skin material having a plurality of different portions in such a manner that each boundary line of the different portions is hidden in a groove or valley provided in the substrate of the trim component, which comprises a pair of confronted molding dies; a carrying-in device for introducing the surface skin material into a space between the confronted molding dies in such a manner that the boundary line of the surface skin material is positioned in engagement with the corresponding internal projection formed on a molding surface of either one of molding dies; a thrust mechanism including a thrust member assembled within the other molding die to be projected from its molding surface toward the internal projection of the confronted molding die and retractable therefrom and an actuator mounted to the other molding die for forwarding the thrust member toward the internal projection so that a distal end of the thrust member is brought into engagement with the boundary line of the surface skin material to retain the surface skin material in place on the internal projection of the confronted molding die; an injection device mounted to the other molding die for injecting melted synthetic resin into a space between the molding dies clamped with each other to form the substrate of the trim component with the surface skin material; wherein the carrying-in device is operated to introduce the surface skin material into the space between the confronted molding dies and retracted to the exterior after the thrust member was brought into engagement with the boundary line of the surface skin material, and wherein the thrust member is maintained in engagement with the surface skin material until the melted synthetic resin is injected by operation of the injection device.
In the production apparatus of the interior trim component, it is preferable that wherein the surface skin material is in the form of plural kinds of surface skin materials preliminarily spliced at their edge portions, wherein the carrying-in device is operated to position the spliced portion of the surface skin material in engagement with the corresponding internal projection of the molding die, and wherein the thrust member is forwarded by operation of the actuator to retain the surface skin material in place in the molding die at its distal end. It is also preferable that the molding surface of the other molding die is formed with a boundary recess corresponding with the internal projection of the confronted molding die and that the distal end of the thrust member is located to coincide with a bottom of the boundary recess in a condition where the actuator of the thrust mechanism is inoperative and forwarded toward the internal projection of the confronted molding die by operation of the actuator.
It is further preferable that the thrust member is formed at its distal end with a recess for engagement with the surface skin material at its boundary line positioned in place on the internal projection of the molding die. In addition, the one of the molding dies may be formed at its molding surface with an addition internal projection for engagement with) a peripheral edge portion of the surface skin material retained by engagement with the first-named internal projection in a condition where the molding dies were clamped. In such a case, the thrust mechanism is further provided with an additional thrust member assembled within the other molding die to be projected from its molding surface toward the additional internal projection of the confronted molding die and retractable therefrom and an actuator mounted to the other molding die for forwarding the additional thrust member toward the additional internal projection so that a distal end of the additional thrust member is brought into engagement with the peripheral edge portion of the surface skin material to retain the surface skin material in place.